<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <script>
        function foo(b) {
        let a = 10;
        console.log('foo')
        return a + b + 11;
        }

        function bar(x) {
        let y = 3;
        console.log('bar')
        return foo(x * y);
        }

        console.log(bar(7)); // 返回 42
    </script>
</body>
</html>